Device for preventing carburetor fires



Jan. 31, E933. F. SCHWEIZER DEVICE FOR PREVENTING CARBURETOR FIRES Filed Aug. 6, 1930 Inventor. fianz Scfiweizer,

Patented Jan. 31, 1933 UNITED STATES PATENT OFFICE.

FRANZ sonwmzm, or nor, GERMANY, ASSIGNOR rro KARL HINTSCVH'E'S, or claimxo'rzau, GERMANY I 1 DEVICE roe PREVENTINGTCAR-BURETOB rmas" Application filed August 6, mo, Serial no. 473,498, and. in Germany June 26, 1980.

v '-Attempts have been made repeatedly'to gerous temperature.

reduce to a minimum the danger resulting from the frequently occurringv carburetor-. or motor-fires on motor cars and the like. The cause for carburetor fires is any irregularity of the motor whereby the ignited or incandescent gas mixture flows from the cylinders through the feed pipes into the carburetor and ignites the explosive mixture in the same, whereby further ignition of the fuel inthe fuel feed pipes and in the tank is caused, so that the car is destroyed and serious or deadly injuries of the passengers and driver happen. 7

Even when the motor is attended with care, it happens, especially in-the course of a long service, either that foreign bodies get into the valveseats so that the valve shaft jams in its guides or the valve spring breaks, or incandescent oil-carbon collects in the cylinder.

All these irregularities or defects in the motor cause overheating of the same and eventually, owing to the back firing of the gases from explosionthrough the badly fitting suction valves, fires in the carburetor or even in the tank.

An arrangement is therefore Wanted which, with absolute security, interrupts the fuel admission instantaneously, as soon as the motor is heated above a certain degree, so that fires in the carburetor or in the motor can no longer occur. I I

This invention relates to an apparatus which is arranged in proximity to and above the carburetor and inserted in the fuel supply pipe. This apparatus consists of a valve arrangement, constructed so that the springcontrolled valve body shuts off the fuel supply pipe only whenothe motorblocks or the carburetor has been heated to a temperature, which is excessive but still below the dan- According to the invention the shutting off valve is held open, when the spring is under tension, by an element, Which consists of easily combustible material, possessing however below the ignition point a suflicient resistance to maintain the valve in the open position in opposition to the action of the spring.

As the new apparatus is arranged directly above the carburetor, the element maintaining the valve in the open position directly facing the carburetor, the absolutely secure functionof the apparatus is assured. The easy combustible element will'ignite readily at overheating of the carburetor to, a degree of heatpvhich is not yetdangerous, i. e. before igniting of the carburetor can occur, and the valve liberated by the ignited element will shut off thefuel admission to the carburetor.. q I I An embodiment of the invention is illustrated by way of example in the accompanying drawing in which: v v

Fig. 1 shows in frontelevation the apparatus to be inserted into the fuel supply pipe ofthe carburetor. a 1

Fig. 2 shows acentral vertical section of the apparatus, the valve being in the open position. 1 W

Fig. 3 is a similar view asFig. 2, the valve being closed.

v The apparatus, according to the invention, consists of a short tube a with tubular sockets b and 0. The short tube a has an enlarged lower end (i. In the tube a a bush 6 is inserted, the lower end of which isflush with the inner surface of the enlarged portion (1, and a spindle f of the valve body 9 is guided in this-bush, into which it fits closely. A

pressure spiral I spring h is wound around the spindle, hearing at the upper end against the valve body 9 and at the lower end against the bush 6. The lower'portion i. ofithe spindle f, projecting into the enlarged part d of tube a, is screw threaded and extends through a central hole of adisc lathe rim of which engagesin a groove m in the lower end of the enlarged part d'of the tube a. A nut n, screwed'on the screw threaded part i of the spindle f below the disc 70,-serves for loweringthe'valve body'g in opposition to the action of spring h. The disc kj is made of an easily ignitible material, such as celluloid, possessing however sufiicient resistance to maintain the valve body gin the openposition in opposition to the action of spring h.

On the lower externally threaded portion of the enlarged part d of tube a a screw cap 0 is screwed, which has a large aperture 1) in its bottom plate through which a semispherical segment or cap 9 projects, the edge of which is clamped between the screw cap 0 and the end of part (Z. This semi-spherical segment 9 is preferably made of thin uncombustible material possessing a good heat conducting property. This semi-spherical segment might however also be made of easily combustible material, such as celluloid.

The fuel supply pipe 1 from the tank is connected with the tubular socket Z) by a connecting nipple 8. To the tubular socket c a connecting tube 2? is connected by means of a nipple u, the other end of tube t being connected to the carburetor 'v.

The operation is as follows:

If, for any reason whatsoever, excessive heating of the motor should occur, which might result in a carburetoror enginefire, the disc is will ignite, and also the spherical segment 9, if the same is made of celluloid. As soon as the disk has been ignited, the valve body 9 is released and will be lifted by the action of the spiral spring h into the position shown in Fig. 3 and interrupt the communication between the fuel supply pipe rand the connecting tube t of the carburetor o, i. e. between the benzine tank and this carburetor. so that no carburetor fire can occur or, if a' carburetor fire has started, this fire is instantaneously extinguished, as no fuel is fed to the same.

- The apparatus can be easily made ready for renewed use by removing the screw cap 0 and the nut n, whereupon a fresh disc is is pushed on the spindle i and secured in position by means of the nut 91, which is tightened until the valve body g has been sufficiently lowered against the opposition of spring h to reestablish the communication between the fuel tank and the carburetor. The semispherical segment 9 is inserted and the screw cap 0 screwed on.

I claim V 1. An apparatus for preventing carburetor fires,comprising in combination with the fuel supply pipe from the fuel tank and the pipe connected to the carburetor, a short tube connecting the adjacent ends of said pipes and having an enlarged lower end, said tube having an annular groove near the lower end of its inner surface, a guide bush in said tube, a valve spindle closely fitting and guided in said bush, a valve carried by said spindle and tending to move to a position to shut off the flow of fuel through said pipes, a screw threaded lower end of said valve spindle, a celluloid disc having a central hole pushed over the lower end of said valve spindle and engaging in said groove in the inner surface of said enlarged portion, and a nut screwed on the end of said screw threaded spindle below said celluloid disc.

2. An apparatus for preventing carburetor fires, comprising in combination with the fuel supply pipe from the fuel tank and the pipe connected to the carburetor, a short tube connecting the adjacent ends of said pipes and having an enlarged lower end, said tube having an annular groove near the lower end of its inner surface, a guide bush in said tube, a valve spindle closely fitting and guided in said bush, a valve carried by said spindle and tending to move to a position to shut off the flow of fuel through said pipes, a screw threaded lower end of said valve spindle, a celluloid disc having a central hole pushed over the lower end of said valve spindle and engaging in said groove in the inner surface of said enlarged portion, a nut screwed on the end of said screw threaded spindle below said celluloid disc, a screw cap screwed on the lower end of said enlarged tube part having a large central aperture in its bottom plate, and a semispherical cap held at its edge between said screw cap and the lower end of said enlarged tube part and projecting through said central aperture of said screw cap.

In testimony whereof I aflix my signature.

FRANZ SGHWEIZER. 

